The present invention relates to absorbent articles such as disposable diapers, and more particularly to absorbent articles that have a longitudinally pleated liner to provide improved containment.
The major function of absorbent articles, such as disposable diapers and adult incontinent briefs, is to absorb and contain body exudates. Such articles are intended to prevent body exudates from soiling, wetting, or otherwise contaminating clothing or other articles, such as bedding, that come in contact with the wearer. The most common mode of failure for such products occurs when body exudates leak out of the gaps between the absorbent article and the wearer""s leg or waist to adjacent clothing because they are not immediately absorbed within the article. This is most evident with loose fecal material which is not easily absorbed by the absorbent article and tends to ride on the top surface of the absorbent article. Several solutions to this problem have been proposed.
For example, U.S. Statutory Inv. Reg. No. H1511 describes a flow regulator for an absorbent article that is positioned between the topsheet and the absorbent structure. The flow regulator is described as enhancing movement of fluid in the longitudinal direction while controlling movement of fluid in the transverse and z directions.
U.S. Pat. No. 4,808,177 describes a disposable diaper that has elastically contractible leg cuffs and a pair of floating inner cuffs that are positioned inboard of the leg cuffs to provided containment characteristics. The floating inner cuffs include a cuff layer, a base layer underlaying the cuff layer, a first seam that affixes a portion of the cuff layer to the base layer, a central seam that affixes another portion of the cuff layer to the base layer, an unadhered stand-up portion of the cuff layer between the first seam and the central seam, and a central elastic member subjacent the unadhered stand-up portion that has a pair of affixed portions and an unaffixed portion between the pair of affixed portions. A particular disadvantage to this proposed solution is that the diaper does not lay flat and therefore presents a packaging obstacle.
U.S. Pat. No. 4,892,536 describes a disposable diaper that has elastic strands disposed longitudinally nonadjacent a passageway on the liner so that the fit of the diaper is improved. The passageway permits communication of solid waste through the liner.
U.S. Pat. No. 4,895,568 describes an absorbent article with a resilient barrier member located in the intermediate section of the article. The barrier member includes transversely distributed elastic members that are connected to the liner layer to gather the liner and form ruffled panel regions, which define a plurality of transverse folds to inhibit longitudinal movement of body exudate between the front and the rear waistbands. The elastic members have an active longitudinal extent of not more than about 50 percent of the total length of the article. The barrier member does not inhibit lateral movement of body exudate.
U.S. Pat. No. 5,037,415 describes a diaper that has two longitudinal strips extending in the stretched state over the entire length of the diaper along the opposite longitudinal edges of the pad and disposed between the backsheet and the liner. Elastic elements are attached along the longitudinal length of the strips to define leg cuffs.
U.S. Pat. No. 5,451,219 describes a stretchable diaper that includes a liquid impermeable elastic sheet having a nonwoven fabric secured to the elastic sheet in a continuous manner in one direction and intermittently in a second direction transverse to the first direction so that a plurality of parallel channels extend in the first direction. Absorbent material may be disposed in the channels.
PCT Application No. WO 96/00545 describes a sanitary napkin having an absorbent body and a liquid permeable layer that is provided with longitudinal folds that are formed by using a folding device. The folds have foot areas that are attached to the absorbent body or to a support layer that lies between the absorbent body and the liquid permeable layer.
While the above designs are for the most part acceptable, there still remains a need for a disposable diaper having improved containment.
In accordance with the present invention, a disposable absorbent article such as a diaper is provided. While the present invention will be particularly described in the form of a diaper, one of skill in the art will appreciate that it may be advantageously used with incontinent briefs, diaper holders, training pants, and the like. Generally, the absorbent article comprises a liquid impervious backsheet layer, a substantially liquid-permeable liner layer, and an absorbent structure disposed between the backsheet and liner layers. The backsheet and liner layers generally define a front waistband section, a rear waistband section and an intermediate or crotch region interconnecting the front and rear waistband sections with the intermediate or crotch region being disposed between a pair of leg openings, which may be elasticized.
Portions of the liner layer are adhered to the absorbent structure in a spaced apart longitudinal fashion to define a plurality of laterally alternating adhered liner portions and unadhered liner portions. The adhered liner portions may be intermittently or continuously adhered to the absorbent structure along at least a portion of their longitudinal length. In any event, throughout the following description and claims, except where expressly stated, the term adhered portion refers to that portion of the liner that is adhered to the absorbent structure either intermittently or continuously along at least a portion of its longitudinal length. The liner may also be directly or indirectly adhered to the absorbent structure.
At least one longitudinally extending elastic member is associated with and located subjacent at least some of the unadhered portions of the liner layer to create stand-up ridges. Preferably, at least one elastic member is associated with each unadhered portion of the liner layer. Thus, a plurality of longitudinal ridges are provided transversely across the intermediate or crotch region of the diaper. In one embodiment, the height of each ridge is substantially the same. In another embodiment, the height of each ridge may differ to create a ridge across the lateral dimension of the absorbent structure.
In a preferred embodiment, each elastic member has a front end, a rear end, and a central portion interconnecting the front and rear ends. The front and rear ends are in a relaxed state (i.e., they are not in an elastically contractible condition) while the central portion is in an elastically contractible condition. Preferably, the central portion includes a first end and a second end, with each of the first and second ends adhered to the liner to define a region of the elastic member between the first end and the front end and between the second end and the rear end that is in a relaxed state. More preferably, the central portion between the first and second end is intermittently adhered to the liner to operably gather the liner and form a ruffled ridge.
The present invention, therefore, advantageously provides a plurality of longitudinal ridges, the peaks of which will closely fit to the surface of the wearer""s skin and will aid in reducing skin contamination by separating the skin from the absorbent pad. The troughs (or valleys) created by the upstanding ridges define lengthwise pockets to contain fecal matter and other body exudates and to create barriers that may reduce lateral movement of fecal matter toward the legs, Which should reduce leakage in the leg area. The ridges may also conceal fecal matter when the diaper is removed. Because the front and rear ends of the elastic members are in a relaxed state, the diaper is able to lie flat and will not curl so that is easier to put the diaper on the wearer.
In one embodiment of the present invention there is provided a disposable absorbent article with a front waistband and a back waistband being spaced from each other prior to installing the article on a wearer and a crotch portion disposed in a longitudinal direction between the front waistband and the back waistband and disposed in a lateral direction between a pair of leg openings. The article includes a liquid impervious backsheet; a liquid pervious bodyside liner having a body facing surface and a garment facing surface, wherein the garment facing surface has a plurality of spaced apart longitudinally extending adhered portions located in the crotch portion of the article to define a plurality of laterally alternating adhered and unadhered portions in the crotch portion of the article; an absorbent structure disposed between the liner and the backsheet; and, at least three elastic members disposed between the liner and the absorbent structure and comprising a front end, a rear end and a central portion disposed between the front and rear ends with the central portion being in an elastically contractible condition, each of the elastic members associated with and positioned subjacent an unadhered liner portion wherein each of the elastic members causes the respective associated superjacent unadhered liner portion to be spaced away from the absorbent structure forming at least three ridges.